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Giving Shad a 30-Year Chance

State and federal wildlife officials have a rare opportunity to stem the decline of American shad on the Susquehanna River, a Chesapeake Bay tributary crucial to annual spawning runs.

Populations of the species have historically suffered from industrial pollution and overharvesting by recreational anglers, but losses on the East Coast have increased in recent decades from offshore commercial mackerel fishing and hydroelectric power plants on freshwater migration routes.

Energy companies are now negotiating with the Federal Energy Regulatory Commission for 30-year license renewals for three plants in Maryland and Pennsylvania, a process that will enable the United States Fish and Wildlife Service, corresponding state authorities and private sector conservationists to demand improvements to existing fish ladders.

“It’s a once-in-a-lifetime opportunity to leverage changes that will help move shad and other migratory species,” said Andrew Shiels, deputy director of field operations for the Pennsylvania Fish and Boat Commission, a stakeholder in relicensing negotiations. “We won’t have a chance like this again for another 30 years, so we have to be on the right track.”

Shad numbers on the Susquehanna in the past decade alone have tumbled from 600,000 in one year to a record low of 19,000, largely because fishways approved in the last licensing period have been ineffective, Mr. Shiels said. “Thirty years ago,” he said, “these fishways were considered the be-all and end-all, but we now know more than we did then. For instance, water coming through a fishway has to be stronger than on the rest of the river, because shad are attracted to current flow.”

Shad migration success varies from one dam to the next. For instance, at Safe Harbor Hydroelectric Station — which has secure licensing — long-term passage for shad averages at 72 percent, while York Haven is as low as 7 percent, Mr. Shiels said.

“Allowing for some loss of fish along the way, our goal going forward is to see 75 percent of shad make it to their spawning ground.”

The fish and boat commission, American Rivers and the Nature Conservancy have helped design the water flow and fish-tracking studies that Exelon and Olympus Power will conduct through next year to determine the best operational or infrastructure changes to make that happen. Improvements also would enhance the migration of hickory shad, American eels and other anadromous species, Mr. Shiels said.

“The energy companies’ burden is to get fished passed,” he said. “Our burden is to give guidance.”

Options could include replacing or retrofitting older fishways with newer technologies, increasing the number of passage devices, performing trap-and-transfer of shad and altering water flow, Mr. Shiels said. “We’re likely to suggest a variety of tools, but we don’t have the recipe yet.”

An approach being implemented by PPL Corporation as part of the $440 million expansion of its Holtwood hydroelectric power plant on the Susquehanna could prove instructional to other facilities.

“Shad aren’t jumpers like salmon; they prefer elevators,” said Chris Prose, a site supervisor at Holtwood, who indicated that the new plant will enhance the performance of a fish lift constructed in 1997 to move shad and other species over a 2,400-foot-long dam.

A deep, mile-long river channel now being dredged downstream of the plant to improve energy generation is also expected to direct more shad to the fish lift.

“For shad, it’s all about flow,” Mr. Prose said. “The channel will put velocity in the water for shad to traverse, and minimize spill-over across our dam, which causes fish to scatter and fail to find the lift.”

Holtwood has passed as few as 4 percent of available shad a year, but has averaged 30 to 33 percent over the long-term, Mr. Porse said, adding, “We’re hopeful we can improve that.”

The new Holtwood facility is expected to be operational in 2013, the same time license proposals for Conowingo, Muddy Run, and York Haven are submitted to federal energy commission for preliminary review. The commission is expected take about a year to study the proposals and seek final comments before licenses expire in 2014.

“We’ve been at this since 2008, with a lot of stakeholders putting in a lot of staff hours,” Mr. Shiels said. “FERC is the arbiter of what should be done, but those proposals will go through several iterations until everyone agrees that the right things are being done.”

Correction: November 22, 2011Because of an editing error, an earlier version of this article misidentified as Maryland, rather than Pennsylvania, the state in which Muddy Run Reservoir is located.

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